class Pro1{
	public static void main (String[] args) {
		double d = 2;
		double low = 0, high = d;
		double mid = 0;
		for(int i=1;i<=1000;i++){
			mid = (low + high)/2;
			if(mid*mid<d) low = mid;
			else                high = mid;							
		}
		System.out.println(mid);
		
		                    
	}
}